Portsmouth's revival of council house building

Just under 10 years ago, Portsmouth City Council (PCC) reported a staggering 50% reduction in its social housing stock over the past 30 years, which under Right to Buy had seen 16,000 homes sold to the private market.

Intensifying that challenge is Portsmouth’s island geography, which restricts urban expansion and contributes to a dense population of 5,121 residents per square kilometre—the highest in the UK outside of London.

Since then, the council has embarked on a revival of council house building and acquisition, recently exemplified by Somers Orchard, the new community-chosen name for a landmark 566-home mixed-use proposal close to the heart of the city centre, which places sustainability and community at its core.

This redevelopment of two former post-war tower blocks, deconstructed following cladding removal in the wake of the Grenfell tragedy and then structural issues, represents PCC’s largest council-led social housing project in the city’s recent history. Approved unanimously in August 2024, the scheme—designed by Karakusevic Carson Architects (KCA)—includes 319 affordable mixed-tenure homes built to Passivhaus standard, a community centre, public realm improvements and 247 private build-to-rent units with supporting commercial facilities.

This project demonstrates a commitment to inclusive and sustainable urban redevelopment. It showcases a new era of council-led regeneration that prioritises community needs, high-quality design and long-term resilience in addressing the UK’s housing challenges.

Before the design phases, the project was selected as one of 14 national pilot case studies to participate in a six-month research programme for the draft National Model Design Code, led by the Department for Levelling Up, Housing and Communities, from April to September 2021. The initiative focused on testing project management processes and community engagement outcomes, aiming to create a practical ‘how-to’ guide for future estate renewal design codes. It strongly emphasised fostering cross-council collaboration and establishing repeatable best-practice design standards.

This set in motion a consciously sensitive and collaborative approach that would continue throughout the design process. PCC brought together internal departments, external stakeholders and the local community to ensure the project reflected shared objectives.

Kieren Majhail, Associate Director at KCA and project lead for the scheme, praised Portsmouth City Council’s landscape, place and community-led approach, which “emphasised its commitment to maximising benefits for both new and existing residents, avoiding a developer-led or merely cost-driven exercise.”

Strong sustainability principles were embedded in the project from the outset, with KCA adopting a holistic, greener, design-led approach throughout the scheme. The wider masterplan, which encourages active travel and features a complex SUDS system integrated into the landscape, targets BREEAM Communities ‘Excellent’ standard.

All 566 homes are designed to Passivhaus standard, with a fabric-first approach applied to design and technical specification. Informed by early stage resident feedback, that frequently cited fuel poverty as a rising concern, KCA used advanced environmental modelling to evaluate a range of sustainable energy strategies, determining that a unit-based heat pump system (MVHR) would best meet each dwelling’s heating and hot water needs while minimising distribution heat loss and overheating. This innovation will not only provide residents with comfortable homes that have intuitive, user-friendly controls—it will also substantially reduce domestic energy consumption and costs.

“Getting Council buy-in to pursue Passivhaus was not easy”, Kieren reflects, highlighting the significant upfront costs associated with MVHR systems compared to traditional block or district energy solutions.

"Despite funding challenges, it is encouraging to see a local authority make a forward-thinking commitment to sustainability, prioritising carbon reduction while improving residents’ quality of life through energy-efficient design." Kieren Majhail

Health, social integration and quality of life were also key project motivators. In collaboration with PCC’s housing team, a comprehensive brief was established for a variety of tenure types, including council-owned general needs, ambulant disabled accessible, wheelchair accessible, supported and sheltered homes. KCA also enlisted the expertise of a health consultant to join its multidisciplinary team to help develop a methodology to assess impact on health that could be tracked throughout the project. This will also prove useful in any post-occupancy evaluation when the building is in use.

Through inclusive community engagement, the scheme aims to enhance the existing social infrastructure and boost the local economy by providing affordable work, retail, and community spaces.

A multi-layered landscape that changes over the seasons ties the neighbourhood together, promoting health and wellbeing through a series of community facilities and playable open spaces within the landscape.

A large-scale council-led project of this type will inevitably face funding complexities. The £120 million scheme will be partially financed through the sale of council-owned land, enabling a third party to develop the private build to rent housing. To maximise funding opportunities, the council strategically split planning applications between private and affordable tenures in order to access more significant Homes England grant funding for the eligible 100% affordable sites. These approaches are expected to contribute enough capital (without excessive market borrowing) to PCC to help subsidise the affordable tenures while accelerating delivery.

Navigating the project through the uncertainty of changes to fire regulations and rising construction costs also required some difficult decisions to be made regarding viability. The project underwent a lengthy redesign process to incorporate a second stair across all blocks, with value engineering carefully exercised to ensure the project maintained its social and environmental benefits.

A comprehensive engagement and co-design strategy was a cornerstone of the design process, developed in collaboration with PCC’s engagement team and anchored by a diverse community panel comprised of local residents, ward councillors and representatives from schools, businesses and charities. Extensive outreach reached over 1,500 participants, including underrepresented groups, through various inclusive activities. This approach successfully addressed initial community resistance to taller buildings, reduced parking and increased density through open dialogue.

Majhail noted that the process was also influential in rebuilding trust in the Council after several stalled proposals across the city and has “positively changed the way they will deliver community-led urban regeneration projects in the future.”

More recently, PCC has approved the development of a community garden for use on the demolished tower site. This initiative will be partially delivered through community infrastructure levy (CIL) funding, secured with the backing of local councillors and the community.

Although construction is still some way off with the tendering process yet to commence, Somers Orchard has already made great strides towards addressing the shortcomings of the post-war development it will replace. Delivering high-density schemes remains a critical priority for Portsmouth City Council now, as it did 60 years ago. However, through its commitment to high-quality design, enhanced building safety and the creation of a sustainable, well-integrated neighbourhood, one hopes that this project will endure well beyond the lifespan of its predecessor.

Of course, Somers Orchard represents just one part of the council’s monumental effort to restore its housing stock and meet the needs of its growing population. Its true success will be measured by how effectively these project outcomes can be adapted and scaled for future regeneration schemes. However, as a starting point, Somers Orchard sets a strong precedent and promising foundation for Portsmouth’s housing future.